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Introduction

Global left ventricular electromechanical dyssynchrony (GLVD) is uncoordinated LV
contraction that reduces the extent of intrinsic energy transfer from the myocardium
to the circulation leading to a reduction in peak LV pressure rise, prolonged total
isovolumic time (t-IVT) and fall in stroke volume [1]. This potentially important parameter is not routinely assessed in critically ill
cardiothoracic patients.

Methods

A prospective analysis of retrospectively collected data in cardiothoracic ICU patients
who underwent echocardiography was performed. In addition to epidemiological factors,
echo data included comprehensive assessment of LV/RV systolic and diastolic function
including Doppler analysis of isovolumic contraction/ relaxation, ejection time (ET)
and filling time (FT). t-IVT was calculated as (60 - (total ET + total FT)) and the
Tei Index as (ICT + IRT) / ET. t-IVT >14 second/minute and Tei index >0.48 were used
to define GLVD [2]. Data are shown as mean ± SD/median (interquartile range).

Conclusion

GLVD that limits cardiac output is common in the cardiothoracic ICU, and significantly
related to mortality. When diagnosed, the underlying cause should be sought and treatment
instigated to minimize the t-iVT (pacing optimization/revascularization/ inotrope
titration/volaemia optimization).